SAFE — No Known Interaction
🟢 SAFE — Selenium and Levothyroxine can be taken together safely.
Evidence level: LIMITED
Selenium and Levothyroxine are safe to take together. No adverse interactions have been reported in medical literature.
No clinically significant interaction between Selenium and Levothyroxine has been documented in medical literature or FDA drug labeling.
No interaction between Selenium and Levothyroxine has been documented. As a best practice, keep a list of everything you take — including Selenium — and share it with your healthcare provider at every visit. This helps them spot potential issues early.
Take levothyroxine on an empty stomach, 30-60 minutes before breakfast. Take supplements at least 4 hours later to be safe.
Higher risk for: elderly with cardiac conditions, those with adrenal insufficiency, recent thyroid dose adjustments, concurrent calcium/iron/antacid use (absorption interference), or narrow therapeutic index sensitivity.
Thyroid medication absorption may be affected by Selenium. Watch for signs of reduced thyroid medication effectiveness: increased fatigue, weight gain, feeling cold, constipation, dry skin, hair thinning, or brain fog. Conversely, if the interaction boosts absorption: nervousness, rapid heartbeat, weight loss, tremors, or heat intolerance. Take thyroid medication on an empty stomach, at least 30-60 minutes before other supplements. When to seek emergency help: Chest pain, very rapid or irregular heartbeat, severe shortness of breath, or signs of thyroid storm (high fever, extreme agitation, racing heart).
No urgent need to discuss, but always keep your doctor informed of your full supplement and medication list. An up-to-date list helps them make the best treatment decisions.
Safe combination. Mineral absorption tip: take calcium and iron at separate times (they compete for absorption). Magnesium is best taken in the evening. Zinc pairs well with meals to prevent nausea. Vitamin C enhances iron absorption.
Selenium and Levothyroxine are safe to take together. No adverse interactions have been reported in medical literature.
Take levothyroxine on an empty stomach, 30-60 minutes before breakfast. Take supplements at least 4 hours later to be safe.
Thyroid medication absorption may be affected by Selenium. Watch for signs of reduced thyroid medication effectiveness: increased fatigue, weight gain, feeling cold, constipation, dry skin, hair thinning, or brain fog. Conversely, if the interaction boosts absorption: nervousness, rapid heartbeat, weight loss, tremors, or heat intolerance. Take thyroid medication on an empty stomach, at least 30-60 minutes before other supplements. When to seek emergency help: Chest pain, very rapid or irregular heartbeat, severe shortness of breath, or signs of thyroid storm (high fever, extreme agitation, racing heart).
Safe combination. Mineral absorption tip: take calcium and iron at separate times (they compete for absorption). Magnesium is best taken in the evening. Zinc pairs well with meals to prevent nausea. Vitamin C enhances iron absorption.
No urgent need to discuss, but always keep your doctor informed of your full supplement and medication list. An up-to-date list helps them make the best treatment decisions.
Or browse the full interaction database (121,000+ pairs).